(An) efficient method for non-equilibrium green's function simulations and applications to atomistic-level FETs

Abstract

In this work, atomistic-level quantum mechanical transport simulations are performed for nanoscale field-effect transistors (FETs) with lateral or vertical heterojunction within the non-equilibrium Green's function formalism. For efficient simulation of such heterostructure FETs, a novel approach is developed where the Green's functions are calculated by complementarily using the two algorithms of the recursive Green's function and the R-matrix. The R-matrix algorithm is extended to seamlessly combine the two methods on the open system, and an algorithm for the electron correlation function based on the extended R-matrix algorithm is also developed. The proposed method significantly reduces simulation time, making rigorous atomistic simulations of heterojunction FETs possible. As an application, device simulations are performed for two-dimensional lateral and vertical heterojunction tunneling FETs modeled through the first-principles density functional theory.